Spectrofluorimetric Study on Inclusion Complexation of 2-Amino-6-fluorobenzothiazole with β-Cyclodextrin

The interaction between 2-amino-6-fluorobenzothiazole (AFBT) and β-cyclodextrin (β-CDx) has been investigated in aqueous solution and in the solid state. The stoichiometry and binding constant of the complex between AFBT and β-CDx in solution were determined by steady-state and time-resolved fluorescence spectroscopy. The FT-IR spectral data and SEM images of the solid complex confirmed the formation of inclusion complex. The proton transfer behaviour of AFBT has been investigated in aqueous and β-CDx solutions.

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Guest-Host Inclusion Complex Formation of 2-, 3-, and 4-Aminobenzoic Acids with Native and Modified Cyclodextrins

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.69.10 ◽

2016 ◽

Vol 69 ◽

pp. 10-21 ◽

Cited By ~ 1

Author(s):

Narayanasamy Rajendiran ◽

J. Thulasidhasan ◽

M. Jude Jenita

Keyword(s):

Inclusion Complex ◽

Inclusion Complexation ◽

Aminobenzoic Acid ◽

Time Resolved ◽

H Nmr ◽

Buffer Solutions ◽

Aminobenzoic Acids ◽

Modified Cyclodextrins ◽

Ft Ir ◽

Uv Visible

The inclusion complexation of 2-aminobenzoic acid (2ABA), 3-aminobenzoic acid (3ABA), and 4-aminobenzoic acid (4ABA) with α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), hydroxypropyl-α-cyclodextrin (HP-α-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) were studied in buffer solutions of differentpHs (pH~1 andpH~7) and it was carried out using UV-Visible, steady-state and time-resolved fluorescence. Dual fluorescence was observed for all the compounds in aqueous and CD medium. All the ABAs forms 1:1 inclusion complex at pH ~ 1 solution and mixture of 1:1 and 1:2 inclusion complex at pH ~7. With CDs, dual luminescence appeared at pH ~ 1 indicates, both NH3+and COOH groups are present in the interior of the CDs cavities. FT-IR,1H NMR, results suggest ABAs formed a stable inclusion complex with the CDs.

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Spectral and Photoprototropic Characteristics of 4-Aminobiphenyl in β-Cyclodextrin

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20040748 ◽

2004 ◽

Vol 69 (4) ◽

pp. 748-758 ◽

Cited By ~ 16

Author(s):

Israel V. Muthu Vijayan Enoch ◽

Meenakshisundaram Swaminathan

Keyword(s):

Excited State ◽

Steady State ◽

Fluorescence Spectroscopy ◽

Inclusion Complex ◽

Ground State ◽

Time Resolved Fluorescence ◽

Neutral Form ◽

Time Resolved ◽

Time Resolved Spectroscopy

The photophysical and photoprototropic behaviour of 4-aminobiphenyl (4ABP) in aqueous β-cyclodextrin (β-CDx) solution has been investigated using steady-state and time-resolved fluorescence spectroscopy. Fluorescence of the neutral form of 4ABP is enhanced due to the formation of a 1:1 complex with β-CDx. The formation of this complex has been confirmed by time-resolved spectroscopy. In the presence of β-CDx, no change was observed in the ground state pKa value but the excited state pKa value changed. Based on its photophysical and photoprototropic characteristics in β-CDx, the structure of the 1:1 inclusion complex is proposed.

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Antioxidant activity of vitamin E enhanced by cyclodextrin inclusion complex

British Food Journal ◽

10.1108/bfj-08-2020-0719 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Weishi Chen ◽

Dong Liu ◽

Lili Zhou ◽

Qiquan Li ◽

Dezhi Wu

Keyword(s):

Antioxidant Activity ◽

Steady State ◽

Vitamin E ◽

Inclusion Complex ◽

Potential Method ◽

Molar Ratio ◽

Time Resolved Fluorescence ◽

Experimental Conditions ◽

Time Resolved ◽

Content Type

PurposeThe study aims to find potential method to enhance the stability and antioxidant activity of vitamins.Design/methodology/approachVitamin E (VE) and β-cyclodextrin (CD) were used to prepare the VE-β-CD inclusion complex via a solution method. The yielded VE-β-CD obtained from optimal experimental conditions was characterized. The mechanism of complex formation and the properties of the complex was investigated by steady-state and time-resolved fluorescence techniques. The antioxidant activity of VE-β-CD was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and compared with pure VE.FindingsThree experimental factors – reaction temperature (T), molar ratio of VE to β-CD (rm) and inclusion time (t) – were studied for the preparation of VE-β-CD. At experimental conditions of T = 60°C, rm = 1:3 and t = 3 h, a maximum inclusion rate of VE (78.62%) was obtained. The Fourier-transform infrared spectroscopy (FTIR) shows that VE molecule was physically encapsulated by β-CD in the yielded product. Subsequentially, the steady-state fluorescence intensity of VE was found to increase upon encapsulation by β-CD due to the hindrance of fluorescence quenching of VE molecules inside the hydrophobic cavity of β-CD, and an inclusion constant K was determined to equal 3.58 × 103 L/mol from the fluorescence results. The fluorescent observation was confirmed by time-resolved fluorescence experiment as the lifetime of VE increased with an increase in β-CD concentration.Originality/valueThe ability of removing radicals by VE was significantly enhanced after the formation of inclusion complex with β-CD.

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